With the rapid development of the Internet technology in recent years, Web systems such as Internet and intranet systems that use WWW have become widely used. In such a Web system, requests and responses for particular processing (for example display of a page) are transmitted repeatedly between a Web browser on a client terminal and a server, thereby various services such as database search or online shopping services are provided.
Such Web systems typically use a connectionless communication protocol such as the HTTP (Hyper Text Transfer Protocol). Therefore a session needs to be established for each process when a series of services including multiple processes is performed. For example, when data is searched for through a Web browser and then a refined search is performed, the first session is closed once a main search page has been displayed on the Web browser, and a new session needs to be established in order to display the next, refined search page.
In such a Web system, in order to associate multiple sessions established for providing a series of services with one another, session information is passed every time a request is sent from a client terminal to a server and every time a response is sent from the server to the client terminal, thereby managing the sessions between the client and the server.
There are various methods for managing sessions. For example as the session management methods, there are URL encoding, server cookies, and hidden fields of HTML. These session management methods are useful in communication between a Web browser on a client terminal and a server.
However, when a local application is running on the client terminal besides a Web browser and the Web browser and the local application cooperate with each other, any of the session management methods cannot be used for managing three-way sessions among the local application, the Web browser and a server since the methods do not have a way to pass processes (sessions) of the local application to the Web browser.
A technique for passing information and sessions obtained from a server to a local application through a Web browser has been proposed, in which an applet on a Web browser and a client-server application (local application) on a client terminal pass information to and from each other through a socket (see for example Japanese Laid-open Patent Publication No. 2006-059267).